1.8 engine tuning

[Niall]

after all this is done, would it not be easier to drop in the '6 lump and loom?

i should imagine the ECU would be able to compensate with the sensors to an extent..

personally (on a more constructive note) i would want a better, more appropriate fueling map for it and that comes with the requirement of a different ECU.

Depends what you want from the engine really. The end power figure isn't the most important thing most of the time (although a lot here seem to think it is lol).
For example, there's no point in having 300hp if it doesn't make that along with peak torque until 7.5k and it's lifeless below that because you have to rag the tits off it everywhere.